Vessel Mooring Safety Procedures and Maritime Terminology

Mooring Operations: Definitions and Safety

What is Mooring Operation?

Mooring Operation: The operation in which a vessel is secured by means of ropes or wires to a fixed point (shore, buoy, or anchor).

Understanding Snap-Back Zones and Rope Bights

How to perform a safe mooring operation? Safety protocols must be strictly followed, especially regarding personnel placement and equipment handling.

What are the Snap-Back Zone and Rope Bight?

• Snap-Back Zone: The area traveled by a parted rope or wire which possesses enough kinetic energy to cause severe injury or death. This zone must be avoided by all personnel.
• Rope Bight: Mooring ropes are long and heavy, often stored in coils. When these ropes are in use, the loop or ring shape they form is known as a rope bight.

How to Avoid Accidents During Mooring Operations

To ensure safety, the following precautions must be observed:

• Crew members must at all times be aware of their standing position when handling ropes or when near them.
• The Supervising Officer must monitor the actions of other crew members and should not involve themselves in the operation as a working hand.
• Inexperienced crew (such as cadets and fresh ratings) should only be allowed to handle ropes under direct supervision.
• Only the essential crew required to perform the operation smoothly should be present at the mooring station.
• Notices should be placed declaring the mooring area as a restricted zone where visitors and unauthorized personnel are not allowed.

Anchoring and Deck Equipment Terminology

Key Definitions for Securing a Vessel

• To Moor: Securing a vessel in a particular place by means of wires or ropes made fast to the shore, to anchors, or to anchored mooring buoys, or to ride with both anchors down.
• Running Anchoring: A method used when anchoring with headway (forward motion) and laying out the anchor cable under the ship.
• Dropping Anchorage: A method in which the anchor is let go, and then the ship is moved astern (backward) while laying out the cable.

Deck Fittings and Machinery

• Deck Fittings: A term used to refer to all objects on deck to which ropes or cables are secured (e.g., bitts, fairleads, cleats).
• Windlass: A mechanical device used to heave up and drop the anchor cable.
• Capstan: A mechanical device, typically vertical, used for moving heavy weights, primarily by means of cables or ropes.

Vessel Movements and Environmental Factors

Six Degrees of Freedom (Vessel Movements)

Vessel movements describe the ship's motion relative to its center of gravity:

• Heaving: The vertical movement of the vessel (up and down).
• Surging: The longitudinal movement of the vessel (fore and aft, toward the bow and stern).
• Swaying: The lateral movement of the vessel (side to side, to the port side and starboard).
• Pitching: The angular rotation about the transverse axis (inclination to the bow and stern).
• Rolling: The angular rotation about the longitudinal axis (inclination to the port side and starboard).
• Yawing: The angular rotation about the vertical axis (rotation of the bow/change in heading).

Weather Conditions at Sea

Key environmental factors affecting ship operations include:

• Current
• Waves
• Wind
• Rain
• Tide
• Dust
• Pressure
• Mist
• Fog

Common Maritime Accidents

Potential hazards and accidents at sea include:

• Man Overboard
• Collision
• Blackout (loss of power)
• Sinking
• Falling Cargo
• Fire
• Capsize
• Grounding